The present invention relates to a coupling adapted to be quickly connected to a cylindrical member and, more particularly, to a coupling for quickly connecting a cement head to a casing of an oil or gas well.
During the completion of an oil or gas well, a cementing operation is carried out in which cement slurry is pumped through the control bore of the well casing and at through ports in the side of the well casing into the annulus formed between the well casing and the bore hole. When the cement hardens it forms a seal between the well casing and the bore hole to protect oil producing zones and non-oil producing zones from contamination. In addition, the cement bonds the casing to the surrounding bore hole providing support and strength to the casing, preventing blowouts, and protecting the casing from corrosion. In one of several typical cementing operations, the well bore and well casing are filled with drilling mud prior to cementing. A cementing plug is pumped ahead of the cement slurry in order to prevent mixing of the drilling mud already in the casing with the cement slurry. When the cementing plug reaches a collar or shoulder stop in the casing, the cement slurry pressure above the plug increases until the plug ruptures enabling the cement slurry to pass through the plug and then through the side ports and into the annulus between the casing and the well bore. Subsequently, another cementing plug is pumped down the casing to prevent mixing of the cement slurry with additional drilling mud which is pumped into the casing following the cement slurry. When the top cementing plug lands on the collar or stop shoulder, the pumping of cement slurry ceases.
In order to perform various cementing operations such as the above cementing operation, it is usually necessary to employ a cement head on top of the well casing. The cementing plugs are held within the cement head until the cementing operation requires their deployment. Known cement heads typically utilize a threaded end for connection to an internally threaded casing. This requires hazardous and often difficult threading operations requiring chain tongs. In addition, the threads can sometimes become damaged during such operations and thereby pose a blowout risk. It is therefore desirable to provide a device for quickly and safely coupling a plug container to a wellhead casing.